Core drill head



J. H. HOWARD ET AL CORE DRILL HEAD Filed May 25, 1954 2 Sheets-Sheet l W $0/ y; ,70C mwa. Wu! fr V@ .L m f f A ///bf f 00 N 7. w

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May 25., 1937- J. H. HOWARD Er Al.V Y I 2,081,201

'- CORE DRILL HEAD Filed May 25, 1934 Sheets-Sheet 2 Patented May -25, 1937 UNITED STATES CORE DRILL HEAD `lohn H. Howard, Huntington Park, and Alfred C. Catland, Alhambra,

Calif., assignors to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application May '25, 1934, seal Nc. 727,500

1I Claims. (Cl. Z55-72) 'Ihis invention relates to a well drilling tool and relates more particularly -to a bit head or cutter head for a core drill. A general object of this invention is to provide a simple, practical 5- and improved core drill head. 'Another object of the invention `is t'o provid a core drill head embodying a plurality of roller cutters mounted in a manner so that they may be easily and quickly replaced.

Another object of the invention is to provide a 'core drill head embodying detachable cutter carrying units rigidly and dependably attached tothe body of the head by'srriallA` sections of weldingand fitted on the head so that the weld# ing is not subjected to'breaking forces duringl the drilling operations. A

Another object of the invention is t'o provide a core. drill head of the character mentioned in which the roller cutters are rotatably mounted on the units and the units are detachably con' nected to the body of the head withoutemploy; ing screw threads.

Another object of the invention is to provide a core drill head embodying a plurality of cutter carriers that may be easilydetached from the head to permit the replacement of, the cutters and their bushings and then easily and quickly reapplied tothe head carrying new or replacement cutters and bushings.

Another object of the invention is to provide a core drill head of the character mentioned in which the detachable units each have a cutterl carrying pin having one end integrally connected to the unit and one end directly bearing on the body of the head.

A further object of the invention is to, provide' a core drill heaglof the character mentioned that is economical in construction and maintenance and that carries or supports its cutters in advantageous positions making the drill rapid and eilicient in operation.

Other objects and features of the invention will be better and more fully understood from the following detailed description of a typical form and application of the invention, throughout which description referencelmay be had to the 1 accompanying drawings, inwhich: 1 f

Fig. 1 is a. s ide elevation of a core drill with one quarter in longitudinal cross section and carry-f ing the headv of the present invention which ,appears in longitudinal crosswsection. Fig. 2 is an enlarged bottom view'of the head withtwo of the cutter carrying u'nits removed. Fig. 3 is a longitudinal detailed sectional view of the head 55 'taken substantially as indicated by line 3-3 on Fig. 2. Fig'. 4 is an elevational view of the inner side of one of the 'carriers' for supporting an inner cutter. Fig. 5 is an elevational view of the inner side of one of the carriers for supporting 60 an outer cutter. Fig. 6 is a side elevation of the head with one of the inner cuttercarriers removed `and with the cutters and bearings removed from the other carriers. similar to Fig. 6 taken at a different rotative position with one of the outer cutter carriers removed and with the cutters and bushingsremoved from the other carriers. Fig. 8 is a side elevation of the carrier of one of the inner cutter carrying units. Fig. 9 is a longitudinal detailed sectional view of one of the inner cutters and lits bushing. Fig. 10 is a longitudinal detailed sectional vlew of one of the outer cutters and its bushing and Fig. 11 is a side elevation of the carrier of one of the outer cutter carrying units.

The present invention is concerned primarilyy with an` improved bit head or cutter head for a core drill. To'facilitate a clear understanding of the invention the head will be described in connection with a more or less typical core drill assembly, it being understood that the inventionv is not to be construed as limited or restricted to the specific form or application about to be described, but is to be taken as including anyfeatures or modiiications that may fall within theA scope of the claims. -A

The coredrill illustrated in the drawings in-` cludes an outer barrel I0, an inner barrel II, a core kcatcher I2, and the cutter head orbit head H of the present invention. The outer barrel I isan elongate tubular structure having a sub I3 at its upper endfor connection' with the drilling string. A connecting A'member or sub I4 is provided on the lowerend ofthe outer barrel and has a screw threaded pin I for carrying or confnecting with the `head H. The inner barrel II 'i is provided to receive the core cut by the bit head and is arranged longitudinally in the outer barrel I0. In accordance with the usual practice an annular space S is provided between the interior of the outer barrel I Il and the inner barrel II.`

The lower end of the inner barrel Il is screwthreaded in the connecting member u. A suitable valve V is provided on the upper end of the inner barrel Il to permit the escape of trapped iluid from the inner barrel and to prevent the downwardly owing circulation fluid'from entering the inner-barrel. The core catcher I2 is arA ranged in the connecting member Il at' the lower -end of the inner barrel II and is operatable to grip and support the core when the drill is raised4 and removed from the well. The core catcher 'fl2 embodies an annular body carrying longitudi- `invention includes, generally, Aa. tubular body 20 on the lower end of the connecting member Il,

Fig. 'I is a view f `in the upper end of the body 20 to receive andries the cutter units A and B whereby the drill is operatable to make an annular cut and form a core to be received in the inner barrel In the preferred construction the body 20 is integral and is annular or tubular in its general configuration. A screw-threaded socket 2| is provided cooperate with the pin I5. A central longitudinal opening 22 is provided in the head 20 to re- Iceive or pass the core. A downwardly facing external annular shoulder 23 is provided on the body 20 between its ends.

The portionof the body 20 below theshoulder 23 is shaped to receive or carry the units A and B. This lower portion of the body 20 is reduced in external diameter and is provided with vertically or longitudinally 'extending series of faces. Each series of faces or surfaces includes a lower substantially vertical face 24 extending upwardly from the lower end of the body. An upwardly and outwardly inclined face 25 extends upwardlyV from each face 24. A at vertical face 26 extends from the upper end of each face 25 to the downwardly facing shoulder 23. The faces 25 which oppose the units A are pitched outwardly at a greater anglethan the, corresponding faces opposing the vunits B. The at vertical faces 24 and 26' are preferably tangent to circles concentric with the longitudinal axis of the tool. In accordance with the invention an opening or socket 21 extends upwardly in the body 20 from the shoulder 23 at the upper-end of each series of faces 24, 25 and 26. The sockets 21 extend parallel with the longitudinal axis of the body 20 and their axes are equally spaced between the opposite vertical edges of the faces 1216. The sockets `21 may be round in cross secs The detachable units A embody the cutters X which are provided to engage the outer pory tion of the bottom of the well bore and the side wall of the well bore to ream or cut the bore to size. The cutters X are frustro-conical roller cutters having flat normal ends and pitched or inclined peripheries. Peripheral cutting parts or teeth 28 are provided on the cutters X. In the particular form of the invention disclosed in the drawings there are four units A each carrying a cutter X. The units A are arranged or positionedin pairs at diametrically opposite portions of the body 20. The teeth 28 of one cutter of each pair are straight or axial while the teeth of the other cutters are spiralled. The spiral teeth of one cutter are pitched -in one direction while the spiralled teeth of the other cutter are spiralled or pitched in the opposite direction.

In accordance with the invention the outer cutters X are supported 'by the units A to rotate about axes' inclined downwardly' and inwardly, as will be more fully described, so that their cutting teeth 28 which project from :the lower end of the body 20 are substantially normal to the longitudinal' axes of the tool as they come into engagement with the earth formation. The cutters X project from the periphery of the body and the outer ends of their cutting teeth 28 are bevelled tor have reaming edges 28. Each outer .cutter X has a central longitudinal opening 29. provided between its ends with an annular *recutter carriers 32V are preferably integral members and are alike in size and configuration. Each carrier 32 includes a. stem 33 projecting from its upper end to t a socket 21. An upwardly facing shoulder 34 is provided at the lower end of the stem 33 and is adapted to seat upwardly against -v the body shoulder 23. A flat vertical face is provided on the inner. side of each carrier 32 at the base of its stem 33. The faces 35 cooperate with the body faces 26 to position the carriers and to prevent turning or swinging of the carriers. The inner sides 36 of the carriers 32 are inclined downwardly and outwardly. In the preferred construction the carriers v32 project outwardly beyond the periphery of the body 20 and their outer sides are cylindrically curved about the central axis of the head.

Each carrier 32 has a stud or pin 31 projecting from its inner side to carry a cutter X. The pins 31 are preferably integral with carriers 32 and project downwardly and inwardly from the lower end portions of the carriers. Bosses 38 are provided at the bases of the pins 31 to space the cutters X from thecarriers and to strengthen the the slots 40 to directly transmit torque and upward thrusts from the inner ends-of the pins 31 to the body 2 0. The slots 40 are initially open at the lower end of the head permitting the easy insertion of the lugs. The ends of the lugs 39 are flush with the wall of the opening 22 while the lower corner portions of the pins 31 are preferably flush with the bevelled end part of the body 20.

Bearing means is provided for rotatably supporting the cutters X on the pins 31. Bushing sections 4| are arranged in the opposite ends of the cutter openings 29 and have ends or shoulders 42 cooperating with the shoulders 3|. The shoulders 42 directly receive end thrusts from the cutters X. A reduced extension 43 is provided on one of the bushing sections to extend through the flange 30 and engage the end of the other bushing section. The bushing sections have aligned grooves or key-ways receiving splines, or feather keys 44. The end portions of the keys 44 are welded to the bushing sections at 45 whereby the keys operate to connect the two sections of each bushing. Keyways 46 are provided in the, pins 31 to receive the splines or feather keys 44. The keys 44 hold the bushings against turning on the pins 31. 'I'he upper or outer ends of the bushings cooperate with the bosses 38 to space the outer ends of the cutters X from the inner sides 36 of the carriers. The inner or lower ends 41 of the bushing assemblies 4| are oblique or inclined to cooperate with the vertical surfaces 24 of the body 20. With the assembly of the bushings 4| and cutter X on the pin 31 of a carrier 32 the carrier may be moved upwardly or parallel with the longitudinal axis of the head to enter itsstem 33 in a socketl and to bring its shoulder 34 against the body shoulder 23. The lug 39 enters the slot 40 and -the oblique end 41 of the bushing clears or slidably engages the body surface 24.

With the carrier in this position the lug 39 is4 welded to the inner wall of the head 20 at 48 to attach the carrier to the head. It will be apparent howthe several carriers 32 carrying the cutters X and bushing assemblies may be readily mounted on the body 20 in the manner just described. The lugs 39 cooperate with the slots 40 to transmit turning forces and thrusts from the end s of the pins 31 directly to the Abody 20 so that the welding 48 is not subjected to any breakfing strains. The Welding 48 merely operates to retain the carriers in the positions where their surfaces 34 and 35 cooperate with the body surfaces 23 and 26. The carriers are fltted to orv arranged on the body 2|! so that they are dependably supported againstfthe strains and thrusts to which they are subjected during the use of the drill.

The units B are spaced between the pairs of l units A, there being two diametrically opposite units B in the assembly illustrated. The units B embodyV the inner cutters Y for engaging the inner portion of the bottom of the well bore and for trimming the core. The cutters Y are substantially cylindrical roller cutters having at normal ends and peripheral cutting teeth 50. The cutting teeth 50 are preferably spiralled-and the teeth of the two cutters Y may be spiralled in" opposite directions. The inner peripheral corners 5l of the teeth 56 may be bevelled o to properly trim the core for passage through the opening 22. Each cutter Y has a central longitudinal opening 52 having an annular restriction or fia-nge ,whose ends form oppositely facing thrust shoulders 53.

Each unit B includes Aor embodies a carrier 54. The carriers 54 are similar, generally, to the carriers 32 but support the cutters Y for rotation about axes inclineddownwardly and outwardly. Each carrier 54 has an upstanding stem 55 on its upper end for tting a socket 21. Upwardly facing shoulders 56 occur at the lower ends'of the stems 55 for tting or bearing upwardly against the body shoulder 23. Flat verticalv faces 51 are provided on the inner sides 'of the carriers 54 adjacent the shoulders 56 for bearing inwardly against the body surfaces 26. The inner sides 58 of the carriers 54 are inclined downwardly and inwardly while the outer sides of the carriers which project fromthe head may be cylindrically curved about the central lon'gitudinal axis of the head. Studs or pins 59 project upwardly and inwardly from the inner sides 58 of the carriers. Bosses 66 are provided on the inner sides of the carriers to surround the inner ends of the pins. The pins are preferably integral with the carriers and their inner ends have direct bearing engagement with the body 20 of the head. Ribs or lugs 6l are provided on the inner ends of the pins 59 to cooperate with slots 62 in the inner wall of the body 29. The lugs 6| co- Y ings and have their opposite ends .welded to the bushingsections to join or connect the two bushing sections of each cutter. The 'outer ends of the bushings \cooperate with the bosses 60 to space the cutters Y from the inner sides 58 of the 5 carriers. The inner ends of the bushings 65 are pitched or inclined to clear or slidably engage the vertical faces 24 of the body. Keyways 61 are provided in the pins 59 to receive the keys 66 of the bushing 'assemblies whereby the keys 66 10 hold the bushing assemblies against rotation.

When the cutters Y and their bushings 65 have been assembled on the pins 69 the carriers 54 are moved longitudinally'or upwardly/to cause the stems 55 to enter the sockets 21, the lugs 15 6| to enter the slots 62, and to. bring the shoulders 56 into engagement with the body shoulder. 23. The oblique -or inclined ends of the bushings 65 allow the carriers to be arranged or positioned 'in this manner. The faces 51 bear against the 20 body faces 26 to position the carriers and sup-V port them against inward thrusts. After the carriers have been set or positioned the lugs 6I are welded to the inner wall of the body 20 at 10. The welding 10 is not subjected to any appre- 25 ciable strains or breaking' forces due to the cooperation of the lugs 6I with the slots 62 and the cooperation of the carrier surfaces with the body shoulders and surfaces. The cutters Y rotatably supported on the downwardly and outwardly in- 30 clined pins 59 through the bushings A65 project from the lower end of the body 20 to engage the formation at the bottom of the well bore and project slightly into the opening 22 to trim the core to pass, into the drill with suitable clearance. 35'

Means is provided for washing or ushing the cutters X and Y. Longitudinal ports 15 are provided in the wall of ,the connecting member drilling string passes from the space S through the ports 15 to the groove 16 where it is distributed to the ports 11.` The passages 18 in the carriers direct the fluid downwardly against the cutters 50 to effectively fiushtheir cutting parts or teeth and to maintain the proper circulation in the well bore.

It isA believed that the operation of the core drill head provided by this invention will be 55 readily apparent from the foregoing' detaileddescription. 'I'he positioning of the several cutters X and Y makes the drill rapid and-efficient in operation. The cutters X operate to cut the well bore to size and act on the major outer por- 60 tion of the bottom of the bore. The inner cutters Y 'rotating' about downwardly and outwardly in` clined axes trim the core and engage the inner portion of the bottom `of the bore. The core cut by the cutters is received in the inner barrel II 65 and recovered in the usual manner by the core catcher l2. During the drilling operation the' cutters X and Y are dependably rotatably supported on their respective pins 31 and 59 through the sectional bushing assemblies. The carriers v32 and 54 Iare firmly and rigidly attached to the body .'26 in manners so that the welds 48 and 10 are not subjectedto failure. The shoulders 34 and 56 cooperate with the body shoulder 23 to transmit upward thrusts from 75 provided with welding equipment.

cooperate with the slots 40 and 62 to transmit torque and thrusts from the inner ends of the cutter carrying pins directly to the body. When 32 and 54 to be slid free' of the body 20. After disconnection of-the carriers from the body 20 theY assemblies of the cutters X and Y and their bushings may be slid or removed from the pins of the carriers. When new or replacement bushings and cutters have been arranged on the pins the carriers may be re-attached to the body 20 in the manner described above whereupon the drill is again ready for use. The cutters-X and Y and the bushing assemblies carrying the cutters may be easily and quickly replaced in any shop Welding equipment is al1 that is required in the replacing of the cutters and bushings.

Having described only a typical -form and application of our invention, we do not wish to be limited or restricted to the specific form and application herein described, but wish it to be of the barrel to form a continuation thereof and having a downwardly facing shoulder, there being a socket in the body extending upwardly from the shoulder, a carrier projecting downwardly in spaced relation to `the side wall of the body and having its 'upper end bearing upwardly against said shoulder, a stem integral with the carrier extending into the socket, a cutter carrying pin on the carrier projecting inwardly from the carrier,

` and means attaching the inner end portionof the pin to the said sidewall of the body.

2. In a well drill, a head having a slot in its lower end, a removable carrier on the head, the carrier including an inwardly projecting pin, a fiat sided projection on the pin h'eld in.the slot in the head to attach the carrier to the head, and a rotatable cutter on the pin.

3. In a' well drill, a head having a shoulder and a slot, a detachable carrier having a face bearing on the shoulder, a pin projecting from the carrier, a rotatable cutter on the pin, and a lug on.

the pincooperating with the slot to transmit thrusts tothe head.

` 4.'In a well drill, ahead having a shoulder and a slot, a detachable carrier having a face bearing on the shoulder, a pin projecting from the carrier, a rotatable cutter on the pin, a lug on the end of the pin cooperating with the slot, and a weld connecting the lug and head.

5. In a well tool, a rigid head whosel lower portion is of reduced external diameter whereby it has a downwardly facing shoulder and a reduced Aexternal surface, a detachable carrier having an upwardly facing shoulder bearing upwardly against the shoulder of the head and having a face bearing inwardly against said surface of the head, a pin projecting inwardly from the carrier, a rotatable cutterpn the'pin, and means connecting the inner end ofthg pin with the inner wall portion of the head o'hold the carrier in position on the head:

6. In a well tool, a head-having a downwardly facing shoulder `and 'an external surfaceand the carriers to the body while the lugs 39 and 6l on tle bushing.

having a slot in its lower end, a detachable carrier bearing upwardly against the shoulder of the' head and having a face bearing inwardly against said surface of the head, a pin projecting inwardly from the carrier, a rotatable cutter on the pin,

lmeans removably connecting the inner end of the pin to the head to transmit torque thereto, said means including a rib on the pin cooperating with the slot, and a weld at the said rib and slot holding the carrier on the head.

7. In a well tool, a barrel adapted to be attached to a drilling string, a tubular head rigidly connected to the lower end of the barrel to form a continuation thereof, the head having spaced sockets, spaced slots in its lower end and downwardly facing shoulders at the mouths of the sockets, carriers arranged on the head to have y their upper ends bear upwardly on said shoulders,

stems rigid with the carriers extending into the vlsockets, pins projecting inwardly from the carriers and cooperating with the head to transmit thrusts thereto, certain of the pins being inclined downwardly and inwardly and others being inclined downwardly and outwardly,.cutters rotatable on the pins, and means connecting the inner ends of the pins to the head including lugs on the pins cooperating with the slots.

8. A head for awel] drill including, a tubular body having a slot in its lower end and a socket spaced above its lowerend, the slot and socket extending parallel with the longitudinal axis of the body, a detachable carrier(` for arrangement on the bodyand including a stem adapted toV` extend into the socket, an inwardly projecting cutter carrying .pin on the carrier,`and a lug on the. inner portion of the pin for cooperating. with thev slot,'the carrier being positioned by movement longitudinally to insert the stem in the socket and the lug in the slot.

9. A head for a well drill including, a tubular body having a slot in its lower end and a socket spaced above its lower end, the slot and socket extending parallel with the longitudinal axis of .body having a slot in its lower end and a socket spaced above its lower end, a substantially at external face on the body, a detachable carrier y inner end bearing on the head, a lug on the inner j end of the pin cooperating with the slot, and a rotatable cutter on the pin.

11. In a well tool, a tubular head, a detachable carrier on thehead, a pin projecting inwardly from the carrier, the 'pin being inclined and having its'inner .end'bearing on a surface of the head, abushing on the pin-havingan end lying in a plane inclined relative to its longitudinal axis and cooperating with said surface for the transmission of thrusts thereto and to prevent rotation of the bushing, and a. rotatable cutter 

